1. Field of the Invention
The present invention relates to a torque responsive rotation control device for use in association with an auxiliary equipment of an engine, or a machine or device driven by a prime mover such as, for example, an electric motor.
2. Description of the Prior Art
As is well known to those skilled in the art, an engine auxiliary equipment is directly driven by a crankshaft of an engine, for example, an internal combustion engine, through a pulley or a gear train, an example of which is shown in FIG. 15.
As shown in FIG. 15, an oil pump 102 which is an auxiliary equipment of the engine 101 includes an oil pump gear 105 meshing with a crank gear 104 mounted on the crankshaft 103 for rotation together therewith. The oil pump 102 shown therein is in the form of a gear pump and is operable to circulate a lubricant oil for the engine 101 in a manner known to those skilled in the art.
As discussed above, the engine auxiliary equipment such as the oil pump 102 is driven directly by the crankshaft 103 of the engine 101 and, therefore, when the engine auxiliary equipment is designed to give a sufficient performance at a low rotational speed of the engine 101, the performance of the engine auxiliary equipment will become so excessive at a high rotational speed of the engine 101 as to result in a loss of the engine output. On the other hand, in terms of the design of the engine auxiliary equipment, the engine auxiliary equipment must be so designed as to ensure the lifetime at a high speed region of the engine at which the performance of the engine auxiliary equipment becomes too excessive and, therefore, not only is reduction in size of the equipment hampered, but also it constitutes a cause of reduction in fuel efficiency.